Changing the dataset on a server executed SSRS Report

I'm trying to narrow down the results returned from a server generated SSRS report, but the customer is requesting too many fields to do be able to do it easily with parameters into a predefined SQL statement.

Is it possible to pass a statement into the reporting server from .NET that the server will execute as its datasource, instead of the preconfigured one? Either the complete statement or the WHERE clause would be fine.

If not, is it possible to eval a parameter sent into a stored procedure? I'm aware of the security implications.

via Chebli Mohamed